根面龋菌斑致病菌在不同pH值条件下的产酸分析  

Major pathogenic bacteria and lactate-producing level at different pH levels of dental plaque on root caries

作　　者：董维理[1,2] 易安华[1] 李成章[1,2] 黄志强[2] 

机构地区：[1]武汉大学口腔医学院口腔生物医学工程教育部重点实验室,武汉市430079 [2]武汉大学口腔医学院牙周科

出　　处：《中华老年医学杂志》2007年第11期831-833,共3页Chinese Journal of Geriatrics

摘　　要：目的通过对根面龋菌斑微生物及其产酸水平的定量分析了解根面龋的致龋机制。方法选择16例老年根龋患者，每例选择患根龋的前牙和后牙各1颗分别刮取冠面和根面菌斑，对变形链球菌和放线菌进行选择性培养、菌落计数，采用酶联仪对稀释菌斑在pH7．0和pH5．5条件下的细菌总量和所产生的乳酸量进行分析。结果根面菌斑中变形链球菌和放线菌检出率分别为87．5％和100％，菌落数均明显高于冠面。在pH7．0时，根面菌斑致病菌产乳酸量为（0．1906±0．1395）mmol／L高于冠面（0．1340±0．0462）mmol／L，但差异无统计学意义（P〉0．05）。pH5．5时，根面菌斑产乳酸量（0．1352±0．0944）mmol／L高于冠面菌斑（0．0427±0．0399）mmol／L，差异有统计学意义（P〈0．05）。结论放线菌和变形链球菌是根面龋的优势菌，在酸性环境下（pH5．5），根面菌斑产乳酸水平高于冠面，提示放线菌和变形链球菌在酸性环境下产酸可能是致龋的主要原因。Objective To explore the major pathogenic bacteria and acidogenic property of root caries through quantitative analysis of the plaque samples. Methods Sixteen elderly patients with root caries assessed by decayed-missing-filed teeth（DMFT）≥ 2 were collected, a incisor and a molar were selected, the plaque were sampled from the crown and root sound surface separately. The colony forming units （CFU） of Streptococcus mutans and Actinomyces were counted by the selected media. The amount of lactate produced at different pH levels were measured with a microlitre plate reader. Results The isolation frequency of Streptococcus mutans and Actinomyces were 87.5%, 100% on the root surface. Both CFU of root surface were significantly higher than that of crown surface. At pH 7.0, the lactate-producing level on root surface was （0. 1906±0. 1395）mmol/L, which was higher than that of crown surface（0. 1340±0. 0462）mmol/L, there was no significance（P〈0.05）. At pH 5.5, the lactate-producing level on root surface was （0.1352±0.0944） mmol/L, which was significantly higher than that of crown surface （0. 0427±0. 0399）mmol/L（P〈0. 05）. Conclusions This study suggests Actinomyces, Streptococcus mutans are the major pathogenic bacteria leading to root caries. At pH 5. 5 the lactate-producing level of dental plaque is higher on root surface than that of crown surface. This indicates that the cariogenicity of Actinomyces, Streptococcus mutans are related to the lactate-producing at acid environment.

关 键 词：牙根龋 链球菌 放线菌科 龋齿 乳酸 

分 类 号：R686[医药卫生—骨科学]